Inguinal hernias in CAPD patients may cause local groin pain, swelling of the groin or genitals, ultrafiltration failure, and even bowel strangulation; however, similar to common hernia symptoms, most hernias in CAPD patients are asymptomatic, which might make them difficult to discover by nephrologists. Current modalities commonly used in studies to identify hernias in these patients include ultrasound, CT, peritoneal scintigraphy and CT peritoneography, and the latter modality is considered the reference standard for diagnosis[6, 7, 15]. Although it has a high detection rate and widespread availability, this modality has limitations; the process requires a strictly sterile technique, and patients need to be exposed to ionizing radiation . Approximately 72% of hernias in this study were diagnosed by ultrasound, which requires an experienced sonographer to perform. Nonenhanced CT can also have good diagnostic value and can be an advantageous supplement for diagnosis (Fig. 1).
To reduce patient discomfort, increase ultrafiltration efficiency and reduce further damage caused by inguinal hernia, timely repair of the hernia in this unique population is advisable[8, 16]. The number of hernias repaired emergently may increase, often combined with bowel resection, whilst awaiting or refusing elective surgery, and mortality and complication rates may also increase[17, 18]. In addition, the patient on CAPD per se is adverse to recovery from inguinal herniorrhaphy. When this circumstance occurs, management is trickier and more difficult. Although, three patients underwent emergency surgery with Lichtenstein procedure for incarcerated hernias and recover well in the study, one patient in the same period had intestinal necrosis due to an incarceration time of more than 24 hours; approximately 15 cm of the small intestine was intraoperatively removed, and simple repair with high ligation of the sac was performed and recurrence was found 2 months after surgery. Besides, the median postoperative hospital stay of emergency surgery was 5 days, which was longer than that of elective surgery.
In this study, we found no recurrences after tension-free mesh repair for inguinal hernia, including those patients who had early resumption of CAPD after repair, which demonstrates that tension-free mesh hernioplasty for CAPD patients is safe and feasible, which is consistent with the findings of other studies[5, 6, 9, 10]. Luk et al. demonstrated that the Lichtenstein mesh repair remains the gold standard for patients with CAPD. Gianetta et al. also claimed that the results of the Lichtenstein technique under local anesthesia for these high-risk subgroups are satisfactory. After verification with more patients in this study, we agree with the conclusion of the above studies. Furthermore, considering the unfavorable effect of uremia on wound healing, patients on CAPD are especially suitable for a minimally invasive procedure, so the Lichtenstein mesh repair should be the first choice. In addition, three patients who underwent the anterior Kugel procedure also achieved satisfactory results in this study. To the best of our knowledge, there is no report in the literature on the application of this surgical technique in the treatment of CAPD patients with inguinal hernia, and this is the first study.
The anterior Kugel procedure takes an anterior approach for preperitoneal repair and is a modified Kugel procedure. The procedure maintains most of the benefits of the standard Kugel procedure, such as strengthening all the defect areas of the myopectineal orifice simultaneously[19, 20]; moreover, the Kugel mesh can be used in limited and closed spaces via fixation by hydrostatic tissue pressure and requires no additional sutures, and the device is inserted into the preperitoneal space, which is contains no nerves or vessels, to avoid nerve and vessel injury. In addition, the technique is suitable for various types of inguinal hernias. This provides a definite theoretical basis for the application of the procedure in CAPD patients. Certainly, application of this technique to repair inguinal hernias requires more familiarity with the inguinal anatomy, and the procedure is more complicated than the Lichtenstein procedure. However, the procedure is also minimally invasive and could be carried out using local anesthesia, which is of great significance to ESRL patients because some of them often have coexisting serious cardiopulmonary diseases.
A prospective randomized study reported that the recurrence rate between the Kugel and Lichtenstein procedures was not significantly different. The Kugel procedure could eliminate “false” recurrences due to the lack of exploration of a missed hernia and provide the whole myopectineal orifice enhancement. As long as the surgeon is experienced, recurrence should be relatively rare in theory. Based on these circumstances, the Kugel technique is at least as safe as the Lichtenstein procedure. In addition, the procedure is suitable for CAPD patients with femoral hernia, which is difficult to address in the Lichtenstein procedure. No patients who underwent the anterior Kugel procedure experienced recurrence during the follow-up period in this study. In addition, the experience of anterior Kugel herniorrhaphy may be beneficial for laparoscopic hernia repair because both have the same operating space. It has already been reported that laparoscopic mesh repair of bilateral obturator hernias in CAPD patients may be considered a feasible operative approach, which provides a new way of thinking for the treatment of CAPD patients with bilateral inguinal hernia in good condition in the future.
There is no consensus on whether it is necessary to convert to HD or on the time needed to resume CAPD after surgery[4, 6, 9, 10, 16, 23]. One investigation revealed that some centers in the UK received temporary HD postoperatively and that the median duration of resuming CAPD was 4 weeks (1 day - 8 weeks). In contrast, some studies advocated the conversion to intermittent PD for 2-4 weeks after surgery before restoring the preoperative CAPD regimen [6, 24]. Other studies have promoted postoperative PD schemes in which patients receive low-volume and high-frequency exchanges with a gradual regain of the preoperative CAPD regimen in 2 - 4 weeks[9, 16]. The last protocol was similar to that of our patients who received low-exchange volumes (1.0-1.5 L) and high-frequency exchanges (5-6 exchanges per day) from 1-3 days after surgery for 2 weeks with gradual resumption to the original CAPD regimens within 4 weeks. The early recurrence and dialysis leakage predicted by the scholars who advocated the conversion to HD did not occur. This has profound significance for these patients because it avoids the pain and risk of establishing and maintaining vascular access, reduces the consumption of medical resources and shortens the hospital stay. We consider that CAPD might be recovered early after surgery without immediate adverse effects on tension-free mesh repair for inguinal hernias.
Patients with ESRL often have poor nutrition, poor immune function, and poor wound-healing ability. In addition, due to the frequent infusion of peritoneal dialysis and the presence of prostheses as foreign bodies, infectious complications are likely to occur, particularly if the sterile technique needed for hernioplasty is not strict enough. We did not observe any wound or mesh infection in our group of patients after treatment with antibiotic prophylaxis, which was consistent with the findings of other studies[6, 9]. Although there were two patients in our study who developed bacterial peritonitis 2 and 3 months after hernioplasty, considering the time interval between surgery and infection, we believe that the infection was not related to surgery, as observed in the other studies[6, 10]; moreover, both patients were cured after intraperitoneal antibiotic treatment without removal of the peritoneal catheter or interruption of CAPD.
Of note, all hernias occurred after the start of CAPD in this study, the reason may be that these high-risk patients who hernias were diagnosed prior to PD catheter placement are often asymptomatic and are reluctant to undergo herniorrhaphy, or even with mild to moderate symptoms, most of them often choose to forbearance because of severe preoperative comorbidities. Simultaneous herniorrhaphy and PD catheter insertion may be a safe and effective treatment regimen for those who pre-existing hernia before the commencement of CAPD[25, 26].
Although the number of patients in the study is limited, the findings verify that tension-free mesh repair is safe and feasible for inguinal hernias in CAPD patients and that only moderate complications occur. The Lichtenstein mesh repair should be the first choice and is also suitable for CAPD patients with severe cardiopulmonary diseases for which general or spinal anesthesia are contraindicated. Anterior Kugel repair may be considered an effective surgical approach if technically feasible. Bridging HD seems unnecessary except for emergency surgery for incarcerated hernias. Using the correct method to address the hernia sac intraoperatively and maintaining close cooperation with nephrologists during the perioperative period are also essential to ensure the success of surgery and resumption of CAPD after surgery.